Figure 5. Framework of power dispatching data network
Figure 6 illustrates the classification and data flow direction of electric power dispatching services. Among them, the services carried on dispatch data network are mainly divided into control area services and non-control area services. Typical control area services include electric power monitoring system and management of safety device, five-protection device, relay protection device, phasor measurement unit (PMU), etc. The data transmission time delay requirement for such control area services is at millisecond or second level, using real-time subnets or dedicated channels of data transmission. Typical non-control area services include online status monitoring, auxiliary monitoring system, the management of electricity metering terminal and fault waveform recorder, etc. The time delay requirement of such services is at minute or hour level, using non-real-time subnets of data transmission.